---
description: >
  The amazon-ebssurrogate Packer builder is like the chroot builder, but does
  not

  require running inside an EC2 instance.
layout: docs
page_title: Amazon EBS Surrogate - Builders
sidebar_title: EBS Surrogate
---

# EBS Surrogate Builder

Type: `amazon-ebssurrogate`

The `amazon-ebssurrogate` Packer builder is able to create Amazon AMIs by
running a source instance with an attached volume, provisioning the attached
volume in such a way that it can be used as the root volume for the AMI, and
then snapshotting and creating the AMI from that volume.

This builder can therefore be used to bootstrap scratch-build images - for
example FreeBSD or Ubuntu using ZFS as the root file system.

This is all done in your own AWS account. This builder will create temporary
key pairs, security group rules, etc., that provide it temporary access to the
instance while the image is being created.

## Configuration Reference

There are many configuration options available for the builder. In addition to
the items listed here, you will want to look at the general configuration
references for [AMI](#ami-configuration),
[BlockDevices](#block-devices-configuration),
[Access](#access-configuration),
[Run](#run-configuration) and
[Communicator](#communicator-configuration)
configuration references, which are
necessary for this build to succeed and can be found further down the page.

### Required:

@include 'builder/amazon/ebssurrogate/Config-required.mdx'

### Optional:

@include 'builder/amazon/ebssurrogate/Config-not-required.mdx'

### AMI Configuration

#### Required:

@include 'builder/amazon/common/AMIConfig-required.mdx'

#### Optional:

@include 'builder/amazon/common/AMIConfig-not-required.mdx'

### Access Configuration

#### Required:

@include 'builder/amazon/common/AccessConfig-required.mdx'

#### Optional:

@include 'builder/amazon/common/AccessConfig-not-required.mdx'

### Run Configuration

#### Required:

@include 'builder/amazon/common/RunConfig-required.mdx'

#### Optional:

@include 'builder/amazon/common/RunConfig-not-required.mdx'

### Block Devices Configuration

Block devices can be nested in the
[ami_block_device_mappings](#ami_block_device_mappings) array.

@include 'builder/amazon/common/BlockDevice.mdx'

#### Optional only for [launch_block_device_mappings](#launch_block_device_mappings)

@include 'builder/amazon/ebssurrogate/BlockDevice-not-required.mdx'

#### Optional:

@include 'builder/amazon/common/BlockDevice-not-required.mdx'

### Communicator Configuration

#### Optional:

@include 'helper/communicator/Config-not-required.mdx'

@include 'helper/communicator/SSH-not-required.mdx'

## Basic Example

```json
{
  "type": "amazon-ebssurrogate",
  "secret_key": "YOUR SECRET KEY HERE",
  "access_key": "YOUR KEY HERE",
  "region": "us-east-1",
  "ssh_username": "ubuntu",
  "instance_type": "t2.medium",
  "source_ami": "ami-40d28157",
  "launch_block_device_mappings": [
    {
      "volume_type": "gp2",
      "device_name": "/dev/xvdf",
      "delete_on_termination": false,
      "volume_size": 10
    }
  ],
  "ami_root_device": {
    "source_device_name": "/dev/xvdf",
    "device_name": "/dev/xvda",
    "delete_on_termination": true,
    "volume_size": 16,
    "volume_type": "gp2"
  }
}
```

-> **Note:** Packer can also read the access key and secret access key from
environmental variables. See the configuration reference in the section above
for more information on what environmental variables Packer will look for.

Further information on locating AMI IDs and their relationship to instance
types and regions can be found in the AWS EC2 Documentation [for
Linux](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/finding-an-ami.html)
or [for
Windows](http://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/finding-an-ami.html).

## Accessing the Instance to Debug

If you need to access the instance to debug for some reason, run this builder
with the `-debug` flag. In debug mode, the Amazon builder will save the private
key in the current directory and will output the DNS or IP information as well.
You can use this information to access the instance as it is running.

## Build template data

In configuration directives marked as a template engine above, the following
variables are available:

- `BuildRegion` - The region (for example `eu-central-1`) where Packer is
  building the AMI.
- `SourceAMI` - The source AMI ID (for example `ami-a2412fcd`) used to build
  the AMI.
- `SourceAMIName` - The source AMI Name (for example
  `ubuntu/images/ebs-ssd/ubuntu-xenial-16.04-amd64-server-20180306`) used to
  build the AMI.
- `SourceAMIOwner` - The source AMI owner ID.
- `SourceAMIOwnerName` - The source AMI owner alias/name (for example `amazon`).
- `SourceAMITags` - The source AMI Tags, as a `map[string]string` object.

## Build function template engine variables

For the build function of [template engine](/docs/templates/engine), the following
variables are available:

- `SourceAMIName` - The source AMI Name (for example
  `ubuntu/images/ebs-ssd/ubuntu-xenial-16.04-amd64-server-20180306`) used to
  build the AMI.

-> **Note:** Packer uses pre-built AMIs as the source for building images.
These source AMIs may include volumes that are not flagged to be destroyed on
termination of the instance building the new image. In addition to those
volumes created by this builder, any volumes in the source AMI which are not
marked for deletion on termination will remain in your account.

@include 'builders/aws-ssh-differentiation-table.mdx'
